scholarly journals Technical mitigation measures for sharks and rays in fisheries for tuna and tuna-like species: turning possibility into reality

2016 ◽  
Vol 29 (4) ◽  
pp. 402 ◽  
Author(s):  
François Poisson ◽  
Francisco Abascal Crespo ◽  
Jim R. Ellis ◽  
Pierre Chavance ◽  
Pascal Bach ◽  
...  

Tuna fisheries have been identified as one of the major threats to populations of other marine vertebrates, including sea turtles, sharks, seabirds and marine mammals. The development of technical mitigation measures (MM) in fisheries is part of the code of conduct for responsible fisheries. An in-depth analysis of the available literature regarding bycatch mitigation in tuna fisheries with special reference to elasmobranchs was undertaken. Studies highlighting promising MMs were reviewed for four tuna fisheries (longline, purse seine, driftnets and gillnet, and rod and line – including recreational fisheries). The advantages and disadvantages of different MMs are discussed and assessed based on current scientific knowledge. Current management measures for sharks and rays in tuna Regional Fishery Management Organizations (t-RFMOs) are presented. A review of relevant studies examining at-vessel and postrelease mortality of elasmobranch bycatch is provided. This review aims to help fisheries managers identify pragmatic solutions to reduce mortality on pelagic elasmobranchs (and other higher vertebrates) whilst minimizing impacts on catches of target tuna species. Recent research efforts have identified several effective MMs that, if endorsed by t-RFMOs, could reduce elasmobranchs mortality rate in international tropical purse seine tuna fisheries. In the case of longline fisheries, the number of operational effective MMs is very limited. Fisheries deploying driftnets in pelagic ecosystems are suspected to have a high elasmobranchs bycatch and their discard survival is uncertain, but no effective MMs have been field validated for these fisheries. The precautionary bans of such gear by the EU and by some t-RFMOs seem therefore appropriate. Recreational tuna fisheries should be accompanied by science-based support to reduce potential negative impacts on shark populations. Priorities for research and management are identified and discussed.

2008 ◽  
Vol 66 (1) ◽  
pp. 155-169 ◽  
Author(s):  
Søren Anker Pedersen ◽  
Heino Fock ◽  
Jochen Krause ◽  
Christian Pusch ◽  
Anne L. Sell ◽  
...  

Abstract Pedersen, S. A., Fock, H., Krause, J., Pusch, C., Sell, A. L., Böttcher, U., Rogers, S. I., Sköld, M., Skov, H., Podolska, M., Piet, G. J., and Rice, J. C. 2009. Natura 2000 sites and fisheries in German offshore waters.–ICES Journal of Marine Science, 66: 155–169. The principal objective of sites selected as part of Natura 2000 is to achieve or maintain a favourable conservation status of habitats and species named in the EU Birds and Habitats directives. In the German exclusive economic zone, the habitat types protected by this legislation are sandbanks and reefs; protected species include marine mammals, seabirds, and specific migratory fish species. The ICES project Environmentally Sound Fishery Management in Protected Areas (EMPAS) aims to answer two questions: (i) To what extent do specific fishing activities significantly threaten attainment of the conservation objectives of the Natura 2000 sites? (ii) What management measures would reduce these conflicts and how effective would they be at helping to ensure the favourable condition of these sites? Assessments of fishing impacts on Natura 2000 sites require basic data on the conservation status of individual habitats and species, as well as data for fine-scale distributions of ongoing fishing activities. This paper describes and discusses the process used by the EMPAS project in developing fishery-management plans for each Natura 2000 site in German offshore waters.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Michael J. Moore ◽  
Julie M. van der Hoop

Concern over the well-being of marine mammals at sea has focused on intentional harvests, both in terms of individual welfare and population sustainability. Unintentional mortalities from fishing gear entanglement are primarily seen as a risk to population viability. Additionally, larger whales breaking free of, and subsequently carrying, fixed trap and net gear are subject to a very slow demise, averaging 6 months in the case of the North Atlantic right whale (Eubalaena glacialis). Chronic cases can involve impaired foraging, increased drag, infection, hemorrhage, and severe tissue damage. The individual suffering of these cases appears to be extreme. Thus management measures should go beyond legally mandated conservation measures to include avoidance of such scenarios. Seafood consumers could succeed, where laws have failed, to demand fishing practices that do not kill whales in this manner. The effective absence of such demands would seem to reflect the cryptic nature of these cases to most consumers.


2020 ◽  
Vol 15 (1) ◽  
pp. 721-734
Author(s):  
Do Manh Hao ◽  
Do Trung Sy ◽  
Dao Thi Anh Tuyet ◽  
Le Minh Hiep ◽  
Nguyen Tien Dat ◽  
...  

AbstractLutraria rhynchaena Jonas, 1844 is of great commercial interest, but its reserves have dramatically declined over recent decades. Therefore, there is an urgent need of scientific basis to propose effective fishery management measures and improve artificial aquaculture of the clam. In this study, we investigated the distribution and density of L. rhynchaena, sediment characteristics, and established the clam’s reproductive cycle through monthly observations from August 2017 to July 2018. The study results showed that distribution and density of clams are related to sediment types, and the sediment type of medium sand is likely the best benthic substrate for the clams. The spawning of clams occurred throughout the year with three spawning peaks in January, April and September. For the sustainable management of the clam resource in Cat Ba-Ha Long Bay, the fishery authorities can issue a ban on harvest of the clam in spawning peak months in January, April and September.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1164 ◽  
Author(s):  
Indre Siksnelyte-Butkiene ◽  
Edmundas Kazimieras Zavadskas ◽  
Dalia Streimikiene

Different power generation technologies have different advantages and disadvantages. However, if compared to traditional energy sources, renewable energy sources provide a possibility to solve the climate change and economic decarbonization issues that are so relevant today. Therefore, the analysis and evaluation of renewable energy technologies has been receiving increasing attention in the politics of different countries and the scientific literature. The household sector consumes almost one third of all energy produced, thus studies on the evaluation of renewable energy production technologies in households are very important. This article reviews the scientific literature that have used multiple-criteria decision-making (MCDM) methods as a key tool to evaluate renewable energy technologies in households. The findings of the conducted research are categorized according to the objectives pursued and the criteria on which the evaluation was based are discussed. The article also provides an overview and in-depth analysis of MCDM methods and distinguishes the main advantages and disadvantages of using them to evaluate technologies in households.


2014 ◽  
Vol 1003 ◽  
pp. 230-234
Author(s):  
Feng Long Fan ◽  
Xu Li ◽  
Xu Sheng Yu ◽  
Li Wang

With the development of computer technology, especially the rapid development and extensive application of database technology and computer network technology, the data quantity increases sharply, the accumulation of a large number of data in various fields, and rising fast. Enterprise database or data warehouse has stored a large number of customer data, these data include many aspects of the information of customers, but also contains the advantages and disadvantages of the enterprise operation. If we can use these data quickly, efficiently in-depth analysis and research, to find the rules and modes, to obtain the necessary knowledge from it, will help enterprises to better decision making. The system can successfully excavate students and staff of the tendency of consumption and consumption habits, analyze their satisfaction with each restaurant. The results of system analysis to a certain role for school students and teachers to understand and analyze the condition of daily consumption, so the establishment of this system has great practical value.


2013 ◽  
Vol 33 ◽  
pp. 63-68 ◽  
Author(s):  
L. A. Zapata ◽  
B. S. Beltrán-León ◽  
J. C. Herrera ◽  
P. Jiménez-Tello ◽  
L. M. Prieto ◽  
...  

Abstract. Commercial fishing of small pelagic species in Colombia, mainly "carduma" (Cetengraulis mysticetus) and "plumuda" (Opisthonema spp.), has been recorded since 1970. Both are used to produce fish meal for aquaculture and poultry and for canned foods. These two species are filter feeders, and therefore support higher levels of the food chain (other fish, birds and marine mammals), and artisanal fishermen use them as bait. Between 2005 and 2010, 86.131 t have been captured (X = 14.355 t yr−1), and a strong reduction was noticed in 2009 (6.969 t). Carduma is considered a total spawning species. However, from 1997 to 2000 and from 2008 to date, atypical reproductive behavior of the species has been observed, including partition of the spawning period and the reduction of the volume of eggs and larvae released to the environment. Both situations are linked to thermal anomalies such as El Niño and La Niña events. Therefore, the process of assigning the global quota of extraction has been revised to take into account the reduction of total capture during the last years and the inconsistencies of the reproductive processes. The Ministry of Agriculture reduced the quota by 10%, leaving available a total of 27 000 t for 2010 and reduced it again to 25 000 t for 2011. It is important to maintain the management measures that are already implemented on this resource (bans during reproduction seasons, catch quotas, regulation of mesh sizes for the fishing nets, and limiting the number of new vessels) and considering other measures such as season closure for recruitment and establishment of marine protected areas to further contribute to the sustainability of these fisheries.


2009 ◽  
Vol 12 (9) ◽  
pp. 88-97
Author(s):  
Tuan Ngoc Le

In HCMC, there are 958 factories in 12 industrial parks – export processing zones (IP-EPZ) (2006), 1,011 large factories, 6,202 small and medium factories out of IP-EPZ with 24 various industries. More than 700 factories operate in field of buying and recycling solid waste. Besides, there are 21 licenced and series of unregistered factories operating in field of collecting, transporting, treating, and burning industrial solid waste - hazardous waste (ISW-HW). There is the survey deployed in 24 districts (HCMC). The scope of that inquiry is 278 factories in IP-EPZ, 96 large factories, 1,142 small and medium factories out of IP-EPZ. The quantity of industrial solid waste is 1,044 tons per day with 12 percent of hazardous waste. After analysing the advantages and disadvantages of 05 methods used for predicting the quantity of ISW-HW, according to the ability of collecting data related in HCMC, the research has compared and chosen the best method. The results are: 1,641 tons per day (2010); 3,196 tons per day (2015); 7,318 tons per day (2020). With more and more ISW-HW, doing overall researches in order to establish the effective ISW-HW management measures in HCMC, minimize the negative impacts to environment and public health.


2021 ◽  
Author(s):  
Majed Nahed Alrabeh ◽  
Zulkiflie Bin Samsudine ◽  
Salvador Alejandro Ruvalcaba Velarde ◽  
Faisal Mohammed Alhajri

Abstract The objective of this paper is to present the findings obtained from a detailed engineering evaluation resulting from trial testing two state-of-the-art surface horizontal pumping systems (HPS's) in two water supply wells. The two horizontal pumping systems were deployed as an alternative to downhole electrical submersible pumps (ESPs) to provide the benefits of eliminating ESP workover costs, modularity regarding wellsite deployments, and enhanced maintenance operations. For this trial test evaluation method, two HPS's were deployed to boost water production to the water injection plant (WIP). To ensure a thorough evaluation, the trial test well candidates were designed to accommodate both a subsurface ESP as well as a surface HPS to provide an accurate comparison, and representation, between the different artificial lift methods. The trial test and comparison method described in this paper focused primarily on the following items; maintenance and well intervention requirements, evaluation of operational availability, including potential for cavitation and effects of interference, maximum production rates, as well as root cause engineering evaluations for mechanical seals and cooling unit auxiliary motors. Various best practices and mitigation measures were identified and are presented in this paper. With regard to the results, it was observed that each artificial lift method comprised a set of advantages and disadvantages. The decision on which type of technology to use can be dependent on several factors. Overall, the HPS's demonstrated the ability to supply water production to the WIP. The HPS did experience operational challenges in providing higher production requirements. Additional challenges were also observed in the sealing mechanism as well as the auxiliary cooling unit. Precautionary pump tripping automated protocols were taken to prevent pump cavitation due to sub-optimal intake pressure resulting from possible interference. The HPS, unlike the ESPs, did not require any workover as it is located at the wellsite and therefore resulted in substantial cost savings and was easy to maintain due to its surface application. In summary, this paper adds a new and very beneficial evaluation of HPS's, and highlights best practices and lessons learned to the existing body of literature. The new information discussed in this paper is highly beneficial to engineering selections of artificial lift methods and to the successful implementation of HPS's in the industry.


2020 ◽  
Vol 41 (6/7) ◽  
pp. 565-577
Author(s):  
Magdaline Wanjiru Mungai ◽  
Selikem Sebuava Dorvlo ◽  
Asaph Nuwagirya ◽  
Marlene Holmner

PurposeCopyright exceptions promote access to information by users without breaching copyright. This research paper reviews copyright exceptions in Kenya, Ghana and Uganda and how they influence access to information in libraries. Objectives were to find out the implications of copyright exceptions in Kenya, Ghana and Uganda; advantages and disadvantages of copyright exceptions for libraries; and recommend best practices of copyright exceptions.Design/methodology/approachThis is a desktop research reviewing empirical literature and incorporating authors' experiential knowledge in their information profession. Authors have interrogated copyright exceptions in their home countries' copyright acts, policy documents and peer-reviewed articles on copyright and information access. They analysed the documents as stated to deduce key recommendations regarding ideal copyright exceptions.FindingsThe study established that copyright exceptions do not always improve access as intended because they are inadequate, ignoring key library functions. Major inconsistencies exist in the exceptions in these countries; key terminologies have not been defined; and the concept is not well understood. Librarians lack sufficient knowledge on exceptions, hence lack self-efficacy in educating users. Kenya, Ghana and Uganda should improve and harmonize their copyright acts to cover key library functions.Originality/valueThis study provides in-depth analysis of historical and modern practices of copyright exceptions in the three countries revealing useful comparative insights. Previous studies looked at the issues from individual countries perspective.


2009 ◽  
Vol 5 (2) ◽  
pp. 204-206 ◽  
Author(s):  
Peter J Corkeron

Some interpretations of ecosystem-based fishery management include culling marine mammals as an integral component. The current Norwegian policy on marine mammal management is one example. Scientific support for this policy includes the Scenario Barents Sea (SBS) models. These modelled interactions between cod, Gadus morhua , herring, Clupea harengus , capelin, Mallotus villosus and northern minke whales, Balaenoptera acutorostrata . Adding harp seals Phoca groenlandica into this top-down modelling approach resulted in unrealistic model outputs. Another set of models of the Barents Sea fish–fisheries system focused on interactions within and between the three fish populations, fisheries and climate. These model key processes of the system successfully. Continuing calls to support the SBS models despite their failure suggest a belief that marine mammal predation must be a problem for fisheries. The best available scientific evidence provides no justification for marine mammal culls as a primary component of an ecosystem-based approach to managing the fisheries of the Barents Sea.


Sign in / Sign up

Export Citation Format

Share Document